Unknown Bliss wrote:Before I go ahead and make an implementation is it worth expanding this (RFC) to other things such as the ACP login confirmation, logout confirmation and login confirmation?

I believe it is. And I think it should be user based and not forum based. I.e. It should be an option in the UCP where the user decides to use this feature or not. I prefer not to use it, usually, but I do believe there are people that would love to have it.
Also, the confirmation can appear in the page where the user was redirected to. Just a div that appears to confirm the form submission.
Also, I believe this redirection fould be made using the status code "303 See Other" and the corresponding Location header.